Pneumatic governor for musical instruments.



W. B. & A. E. TUNSTALL. PNEUMATIC GOVERNOR FOR MUSICAL INSTRUMENTS, APPLICATION FILED APR. 10, 1909.

1,088,306, Patented Feb. 24, 1914.

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APPLICATION FILED APR. 10, 1909. LfifififiOG Patented Feb. 24, 1914.

2 SHEETS-SHEET 2.

WILLIAM B. TUNSTALL AND ALBERT E. TUNSTALL, OF WORCESTER, 'MASSACHUSETTS,

ASSIGNORS, BY MESNE ASSIGNMENTS, T NATIONAL PIANO COMPANY, OF BOSTON,

MASSACHUSETTS, A CORPORATION OF MAINE.

PNEUMATIC GOVERNOR FOR MUSICAL INSTRUMENTS.

Specification of Letters Patent.

Patented Feb. 24, 1914.

Application filed April 10, 11909. Serial No. 489,086.

To all whom itmay concern Be it known, that we, WILLIAM B. TUN- -STALL and ALBERT E; TUNSTALL, citizens of the. United States, both residing at Worcester, the county of Worcester and State of Massachusetts, have invented a new and useful Pneumatic Governor for Musical Instruments, of which the following is a specification. 1'0

musical instrument.

The principal objects of the invention are to provide a controlling pneumatic which can be regulated conveniently from the front oft-he key bed so as to'produce both pianissimo and forte, and which will be capable of being operated so as to give crescendo effects and at the same time will be capable of releasing wind in the action and permitting full'power to be employed in rewinding; and generally to improve and simplify instruments of this character.

Further objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which- Figure 1 is a'vertical transverse sectional view of a portion of a musical instrument showing certain features of this invention;

Fig. 2 is a similar view of one of. the striking pneumatics and connected arts; Fig.

3 is a similar view of a cont-r0 ling pneumatic therefor; Fig. 4 is a side view insection of the lever for operating the controlling pneumatic; Figs. 5 and 6 are respectively. front and side elevations of the same lever in operative position.-

The invention is shown as applied to an instrument having an upright case 10, provided with a key-bed 11, tracker 12, music and take-up rolls 13,- as usual. Thetubes 14 from the tracker are connected with a set of vertical channels 15 each turning at right angles around the take-up spool and connected with vertical tubes 17 which extend down to the primary pneumatics 18.

These pneumatics are shown as located in suction chambers 19 and'each as provided with an adjustable member 20 shown in the form of a screw and located on the movable leaf thereof. This member is adapted to engage a gravity valve 21 which controls port 22 1n the suction chamber and is opened by the expansion of the pneumatic This invention relates to a pneumatic.

partly 18. At the same time the valve closes a port 23 which communicates with the atmosphere. This controls the connectioh of the striking pneumatic 24 with the suction chamber or with the outer air through a passage The valve is kept in place by a flexible member 26 preferably comprising a strip of soft leather secured to the walls of the passage.

Projecting from the movable leaf of the striking pneumatic 24 is a plate 80 having an open ended slot 31 for receiving a rod 32 which connects the striking pneumatic with the action. This rod passes through a stationary guide 34 and is provided with threads 35 preferably rolled thereon on which is mounted a nut 36. This nut can be adjusted as desired and forms with the top .of the guide 34 a'positive stop to limit the collapse of the striking pneumatic, thus preyenting any excess of exhaustion from causmg any damage to the action. The rod 32 is connected with a lever 33 which engages a swinging arm which is pivoted to the abstract 37. The lever 33 is provided with a spring 38 for normally holding the striking pneumatic expanded.

The suction chambers 19 are connected with the exhaust through a controlling pneumatic 40, with which they are con-' heated by tubes 41.

This pneumatic is provided with a port 42 adapted to be controlled by an interior valve 43. This valve is guided by a spider 44 and is adjustably connected with the endof a lever 45 which is located in the controlling pneumatic, and pivoted at a point between its ends. Its other end is provided with an adjustable rod 46 which is secured to the movable leaf of the pneumatic. The controlling pneumatic is exhausted through an outlet 48 connected with the exhaust bellows, not shown.

In order to provide for manually control ling the operation of the controlling pneumatic the following mechanism is shown Projecting from the free end of the movable leaf of the pneumatic is a plate or spring 50 preferably formed of resilient material so that it may have a slight elasticity in operation. Mounted to turn on a fixed portion of the instrument, preferably a bracket 51 on a stationary part of the pneumatic itself, is an eccentric or earn 52 in such position that as it is turned its eccentric surface will be in the path of the plate or spring 50 as tlie pneumatic collapses. Obviously this willlimit the extent of collapse of this pneumatic, so that the operator can produce pianissimo or forte"eifects, and on account of the gradual curve of the eccentric surface crescendo effects may be produced with this device. It will be understood also that by turning the eccentric so as to hold the pneu inatic wide open and prevent any collapse whatever the full force of the exhaust can be secured for double forte. In order to operate this mechanism the cam or eccentric is shown as having an arm or the like connected by a link 5% with link and lever mechanism 55 which terminates in a sliding rod 56 pivotally connected with an arm on the bottom of a lever 58 pivoted on a horizontal axis. This rod 56 extends under the key-bed andthe lever 58 is mounted in a recess in the front thereof. It is swung on its pivot toadjust the cam This lever .is shown as in the form of a hollow casing in which is located a sliding rod 59. The casing is provided with a spring normally pressing this rod up into the position shown in Figs. 5 and 6 in which the parts are in position for operation. The operator controls the pneumatic by manipulating the lever by means of its handle (30. I WVhen it is desired to stop using this device the rod 59 is pressed down, and on account of a pin 61 on-the rod 59 which operates in a curved slot 62 in the casing, this motion causes the rod to be turned through about 90 degrees so that the handle can be held in a position in which it is concealed in the front of the key-bed. A shoulder 63 on the rod engages the bottom of the cylindrical portion of the lever, and on account of the constant force of a spring 64: the rod is moved over to a position indicated in Fig. 4- so that it is held. \Vhen it is desired to use the device a mere touch on the handle will cause the rod to be swung inwardly enough to disengage the shoulder (38 and permit the spring to force the rod up until the head 65 stops it.

While we have illustrated and described a preferred embodiment of-the invention we are aware that many modifications can be made therein by any person skilled in the art without departing from the scope of the invention as expressed in the claim. Therefore we do not wish to be limited to all the details of construction shown and described, but

What we do claim is In a device of the character described, the combination of a pneumatic having a pivoted leaf, a resilient plate extending out fronithe free end of the pivoted leaf, a cam or eccentric mounted to turn adjacent to said plate, and means for operating the cam or eccentric so as to bring difierent parts of its surface into the path of said plate,

whereby the degree of collapse of the pneumatic is controlled.

In testimony whereof we have hereunto set our hands, in the presence of two subscribing witnesses.

WILLIAM B. TUNSTALL. ALBERT E. TUNSTALL. lVitnesses A. E. VAY, C. Fonnns'r VESSON. 

